In many ways Acorn was more important to computing than Apple. The hardware was super elegant and each successive machine improved on the previous generation tremendously and the software was absolutely world class. Just studying the firmware of the BBC Micro made me a far better programmer.

I still think a middle mouse button (actual button, not a wheel) that brings up a context-sensitive menu wherever you are in the window, as used in RISC OS, is much better than the other currently popular ways to implement menus.

Compared to other OSes? Partially. If my memory serves me right, on RISC OS, the middle button menu is the only menu; there is no menu at the top of a window or screen, so it also includes the File, Edit, Help, etc., submenus. So as a concept it is much cleaner. And the right button extends a selection (so you don't have to drag to select, saves your wrist and is more precise), and often has an alternate meaning when clicking on an item, but never gives a menu.

Also good to note that RISC OS had these context-sensitive menus before the Mac or Windows did.

The buttons were Select, Menu, and Adjust! Adjust did different things in different contexts, and i never had a good mental model of why it did what it did.

The other nice thing about the RISC OS menus was that the 'Save As' option (whatever it was called) would pop out a submenu which had an icon of the file in it - you would then drag that icon to wherever you wanted to save it. That struck me as a lovely implementation of the "spatial file manager" idea, and immediately raised the possibility of having other kinds of terminal menus that would do special things.

This screenshot shows both features. The middle button can be pressed on every icon (!Alarm, :0 being the floppy disc drive, the pen and ink, clock etc) plus the editor window.

The icon above "TextFile" would be dragged to a file window. The only file window shows the ROM applications, so it's actually read-only and there's nowhere useful to drag this icon.

Clicking !Alarm etc with the left mouse button selects one at a time, right clicking extends the selection. There are few other things to usefully right click on. The scroll arrows / bar scroll in the opposite direction with a right click. Selecting a menu option from the pop-up menu with a right click keeps the menu open.

The other really nice thing was the anti-aliasing, which was wonderful.

I guess Acorn inventing the ARM chip might give some credence to the GPs point. Acorn were definitely more important in the UK because of the impact of the BBC's Computer Literacy Project - I sit here as a CTO of a software company because of that project. I suspect a large number of the UK's software companies can trace their routes back to that. For the rest of the world I guess the question is open

If you own a Raspberry Pi you can actually boot up RISC OS. Definitely recommend you try it out.[1]

But one thing to keep in mind, the fast boot up, super responsiveness and anti-aliased fonts are not because you're running a 90s operating system on 201X tech, it actually ran that nicely back in the day too.

I often wonder what computing today would look like if different operating systems had gained dominance.

And the low budget Acorn Electron, a kind of stripped down and partially compatible BBC.

As I understand it, the Electron was a bit of a commercial failure. However this caused remaining stock to be dumped (at least in the Netherlands) at rock bottom prices. My primary school teacher was a big fan of them, and installed a couple of them at our primary school. I got to borrow one for a summer break (1990?). My first forays into Basic programming, as well as trying to understand German, since that was the language in which the accompanying Basic manual was written.

That was pretty good as it didn't have a floating point coprocessor at launch and was entirely software implemented. You could buy a card with an AT&T WE32206 copro for it which made it pretty damn fast. I think they had dedicated copro socket later on. I didn't buy one because all of them were stupid expensive.

My folks bought me one for passing my O grades in high school in the summer of 1983. I'd already been hacking away on the school Apple ][ since xmas 1979, then the school BBC's, and it was such a joy to finally own my own computer, and a BBC Model B as well! I learned everything I could about that machine, especially the OS ROM internals. I loved the fact you could just inline 6502 assembler in your BBC Basic programs.

By the time my beeb reached its end of life it had a Torch Z80 co-processor running a clone/lookalike of CP/M-80 (I picked up some dBase II/dBase III work along the way), a pair of high density floppies and loads of other stuff installed. It outgrew even the aftermarket cases and ended up living in a 19" half height Data General mini computer rack (I was very fortunate to work spare hours with a local Data General broker - I even ended up with a full Eclipse S/130 based mini living in my parents house :) ).

For many young people of that time it was a hugely influential machine.

Western Europe, at most. Behind the Iron Curtain, it didn't exist. Among the Western machines, Commodore got a foothold, C16, C64, Plus 4, ZX Spectrum and somewhat the Atari ST and by the end, there were some Amiga 500s.

One of the first computers I ever used was an Acorn, the only thing I can really remember about it was its odd mouse - it had three buttons (no scroll wheel) and both the middle and right buttons provided different context menus!